BIOASSAY/CHEMICAL FRACTIONATION OF TOXIC CHEMICALS IN ST LAWRENCE RIVER SEDIMENT

圣彼得堡马塞纳地区一家铝厂附近收集的沉积物。 劳伦斯河对水生昆虫摇蚊幼虫的致死作用 触须。初步研究表明， 多环芳烃(PAHs)、多氯联苯(PCbs) 和多氯二苯并-对二恶英S/多氯二苯并呋喃 沉积物中的多氯二苯并呋喃不能解释沉积物的毒性。 这项建议的主要目标是确定 沉积物中有毒化合物的生物检测 化学成分。这一新的方法被称为生物测定导向化学 分析可以极大地简化有毒化合物的鉴定 复杂的环境样本。这项任务将在三年内完成 阶段。在第一阶段，将按顺序提取沉积物 用两种极性递增的溶剂(甲苯和甲醇) 用水提取。萃取物将受到一组一组的影响 体内和四种体外生物测定以确定急性毒性， 遗传毒性、雌激素活性/抗雌激素活性和神经毒性。对于 急性毒性测定我们将使用摇蚊幼虫 我们以前工作中使用的程序，以及一种基于 毒剂减少发光物质光输出的能力 细菌。遗传毒性将通过一种不发光的变种进行评估 可以通过突变恢复发光的细菌。 雌激素活性/抗雌激素活性和神经毒性将通过以下方式进行评估 基于MCF-7人乳腺癌生长的哺乳动物细胞系统 细胞和儿茶酚胺在大鼠脑片中的代谢。这个 选定的生物检测方法简单而快速，它们涵盖了一系列重要的 可能对人体健康产生不良影响的生物反应 人类人口。 在第二阶段，提取物将受到化学物质的影响 分级和不同的分级将由 上述生物检测方法。显示增加或减少的分数 相对于它们的提取物的毒性将是 使用最先进的仪器分析有毒化合物，如High和 低分辨率质谱仪与傅里叶变换红外 光谱学。在最后阶段，生物积累和/或代谢 有毒化合物将通过将鱼暴露在沉积物中来确定。 实验室。

Sediment collected near an aluminum plant in the massena area of the St. Lawrence River are lethal to larvae of the aquatic insect, Chironomus tentans. Initial studies suggest that concentration of polycyclic aromatic hydrocarbons (PAHs), polychlorinated biphenyls (PCBs) and polychlorinated dibenzo-p-dioxins (PCDD)s/polychlorinated dibenzofurans (PCDFs) in the sediment cannot account for the toxicity of the sediment. The major objective of this proposal is to determine the complete range of toxic compounds in the sediment using bioassays in conjunction with chemical fraction. This novel approach, termed bioassay-directed chemical analysis can greatly simplify the identification of toxic compounds in complex environmental samples. The task will be accomplished in three phases. In the first phase the sediment will be sequentially extracted with two solvents (toluene and methanol) of increasing polarity followed by extraction with water. The extracts will be subjected to a battery of one in vivo and four in vitro bioassays to determine acute toxicity, genotoxicity estrogenicity/antiestrogenicity and neurotoxicity. For the acute toxicity measurements we will use the Chironomus tentans larvae procedure used in our previous work and also a rapid bacterial assay based ont the ability of a toxicant to reduce light output from a luminescent bacterium. Genotoxicity will be assessed with a nonluminescent variant of the bacterium to which luminescence can be restored by a mutation. Estrogenicity/antiestrogenicity ad neurotoxicity will be evaluated by mammalian cell systems based on the growth of MCF-7 human breast cancer cells and catecholamine metabolism in rat brain slices respectively. The selected bioassays are simple and rapid and they cover a range of important biological responses which could produce adverse health effects in the human population. In the second phase the extracts will be subjected to chemical fractionation and the different fractions will be evaluated by the bioassays described above. Fractions showing an increase or decrease in toxicity relative to the extract from which they were derived will be analyzed for toxic compounds using state-art-instruments such as high and low resolution mass spectrometers and Fourier Transform infrared spectroscopy. In the final phase the bioaccumulation and/or metabolism of the toxic compounds will be determined by exposing fish to the sediment in the laboratory.